|COMP 310 Java Resources Eclipse Resources
Having problems running Java, e.g. blocked by security settings? See the Java Tips and Traps page!
This page is a collection of general resources on the Java language.
The main site for Java is http://www.oracle.com/technetwork/java/index.html
The course always uses the latest version of Java, so be sure that you have updated your JDK!
Since applets and Java Web Start (JNLP files) are no longer supperted at all in the latest Java versions, the following is only for legacy situations and not applicable for most current Java installations.
Java Web Start (JNLP) applications for Java 11+ can be run using OpenWebStart.
Java support for applets (Java programs that run in web browsers) is problematic in 64-bit browsers, e.g. they will not run at all. Installing a 64-bit JDK does NOT install Java support in the 32-bit browser in 64-bit operating systems. Since the 32-bit browser is usually the default browser, this can cause problems in displaying the on-line demos for Comp310 and displaying applets in general.
In Windows Internet Explorer 8, you can tell if Java is installed in the browser correctly by going to Tools/Internet Options/Programs/Manage Add-ins and seeing if the "Java(tm) Plugin 2 SSV Helper" is installed.
To run applets in the usually, default, 32-bit browser, you must install the 32-bit JRE (you don't need the entire JDK), which you can obtain here: http://www.java.com/en/download/manual.jsp
If you are having trouble running applets in the the 64-bit browser, e.g. it fails the verification below, try reinstalling the 64-bit plugin from the link above.
Windows 10 users running the Microsoft Edge browser: Edge does NOT run Java applets, so you will have to switch to Internet Explorer to run the on-line demos in the class web pages: On any page in Edge, go to "More Actions" and select "Open with Internet Explorer".
static Fields or Methods!
Legacy Java 8 installations only:
Notes for Mac users:
JDK 1.8 issues:
Other potential issues:
Notes for Linux users:
Sometime you need to investigate how well your program is running in terms of speed, threads and memory usage. A "profiler" is needed to do this and can be invaluable in both debugging difficult problems such as performance issues, memory leaks and excessive thread usage, as well as for focussed performance optimizations.
© 2020 by Stephen Wong